1. Field of the Invention
The present invention relates to a laminated capacitor and more particularly to a laminated capacitor that is applicable to a high-frequency circuit.
2. Description of the Related Art
The frequency characteristics of a laminated capacitor are determined by its capacitance and inductance components, but generally, it is difficult to realize uniform and good pass characteristics over a wide frequency range.
In FIG. 19, one example of frequency characteristics of a laminated capacitor is shown. The laminated capacitor having the frequency characteristics shown in FIG. 19 has a planar dimension of 1.0 mm×0.5 mm and is a laminated ceramic capacitor having a capacitance of 220 nF that is currently available in the market.
As is understood from FIG. 19, generally, laminated capacitors commonly used have a tendency that the inductance component increases and the pass characteristics (S21 in S parameters) are worsened in the vicinity of 10 GHz and in the frequency range and higher.
On the other hand, for example, in Japanese Unexamined Patent Application Publication NG 2000-243657, a laminated capacitor in which the pass characteristics are attempted to be widened is proposed. This laminated capacitor is favorably used as a capacitor for cutting off DC components in the field of high-speed optical communications and is characterized by the combination of a low capacitance portion and a high capacitance portion.
However, in the laminated capacitor described in Japanese Unexamined Patent Application Publication No. 2000-243657, the pass characteristics are widened to 20 GHz at most and a higher frequency range, for example, a high-frequency range up to 40 GHz cannot be appropriately dealt with.